A first known transmitting and receiving module is disclosed, for example, in German Laid-Open Specification DE 198 23 213. In this already known transmitting and receiving module, a laser (optical transmitting device) and the optically active zone of a photodiode (optical receiving device) are arranged immediately in front of the end surface of an optical waveguide. The photodiode and hence the active zone of the photodiode are integrated in a substrate and have a structure which is in the form of a frame and frames a central region of the substrate. The laser is mounted on the substrate in this central region, as a separate component. From the physical point of view—along the optical axis of the optical waveguide—the laser is thus located between the plane that is covered by the photodiode and the end surface of the optical waveguide. The laser and the photodiode are thus both located in the region of the optical axis of the optical waveguide.
Furthermore, a second known transmitting and receiving module is disclosed in “Optical Transceiver for OP i.LINK S200/S400”, Hideaki Fukita, Yorishige Ishii, Toshihisa Matsuo, Yoshifumi Iwai, Tetsuo Iwaki, Kazuhito Nagura, Takatoshi Mizoguchi and Yukio Kurata; Proceedings of the 11th International POF Conference 2002, Tokyo, September 18–20, in which a deflection mirror is arranged between the optical receiving device and the end face of the optical waveguide. The transmission light from the optical transmitting device is injected without any physical deflection into an edge area of the end surface of the optical waveguide. The transmitting device and the receiving device in this already known transmitting and receiving module do not physically lie on a plane, so that the module has to have a relatively complicated physical design.